"Such print-version rental programs can save a student between 45 percent to 66 percent off the price of a new print textbook, and is often less expensive than digital formats," Schmidt said in a statement.

Textbook rentals from college stores saved students about $450 million during the 2012-13 school year, the association said.

Schmidt said the stores offer other options as well. All sell used books, while some offer free shipping and guaranteed buybacks.

More than three quarters of students prefer print versions of their textbooks to digital, the trade group said.